During the period from December 1, 1995 to November 30, 1996, an additional 56 asymptomatic siblings, age 30-59, of patients with coronary heart disease events under age 60 underwent risk factor screening and testing for occult coronary artery disease (exercise thallium imaging). Risk factor screening included measurement of blood pressure, fasting lipid profile, blood sugar, serum insulin, apolipoprotein B and A1, lipoprotein (a), fibrinogen, spontaneous and ADP induced platelet aggregation, platelet activated IIb/IIIa receptor density, serum thromboxane B2, echocardiogram for left ventricular mass and function, carotid ultrasound, smoking history, resting and signal averaged electrocardiogram, maximal treadmill exercise test with thallium tomography, pre and post-exercise arm/leg blood pressure measurements, Holter monitor for silent ischemia, arrhythmias, and heart rate variability, and changes in blood pressure and heart during the cold pressor and Stroop color word tests. Of the 595 siblings screened since the beginning of this phase of the Sibling Study on 7/25/91, 109 have been African American women, 230 white women, 54 African American males, and 202 white males. Approximately 32% of the individuals screened have been current smokers, 40% had LDL cholesterol > 160 mg/dl, 29% had HDL cholesterol < 40 mg/dl, and about 37% of screenees had hypertension with systolic blood pressure > 140mmHg or diastolic blood pressure > 90mmHg. Eleven percent of the group have had an abnormal exercise thallium scan, and 8% an abnormal exercise electrocardiogram. Only 24% of individuals did not have any of the traditional coronary risk factors. In addition to the initial screening studies, we also performed two-year follow-up risk factor measurements on 44 siblings (16 African Americans, 28 whites), bringing the total number of two-year follow-ups to 220. These follow-ups were done to determine actual changes in risk factor levels resulting from the randomization of these individuals into a nurse- directed multiple risk factor intervention program and a "usual care" treatment arm. The results of these two approaches are being compared to determine the value of the nurse-directed intensive risk factor modification efforts. Based on two-year follow-up data, the nurse intervention group had lower levels of total and LDL cholesterol, more individuals had reduced their LDL cholesterol below National Cholesterol Education Program guidelines, and more were taking lipid-lowering medications. Dietary compliance was also better in the special intervention arm, with lower fat and calorie consumption.